Recently, in a digital (still/video) camera and other electronic devices, for example, a complementary metal oxide semiconductor (CMOS) image sensor is used as a solid imaging device capturing an image.
In the CMOS image sensor, for example, in an analog to digital converter (ADC), an electric signal obtained from a pixel, is compared with a reference signal of which a level is changed, and analog to digital (AD) conversion of the electric signal obtained from the pixel, is performed by using a comparison result between the electric signal and the reference signal.
As described above, the AD conversion performed by using the comparison result with respect to the reference signal, is referred to as reference signal comparison type AD conversion. In the reference signal comparison type AD conversion, the reference signal is used, and thus, a digital to analog converter (DAC) generating the reference signal, is required. For example, a current output type DAC is used as the DAC generating the reference signal (for example, refer to Patent Document 1).